Which of the following is the most suitable title for this passage

A．bulls and bears are now working for people
B．people keep bears and bulls as their pets
C．laws have put stock markets under control
D．people can enjoy their friendship with bears and bulls

A．Origen and Embrex will jointly invent machines to increase production.
B．Origen wants to purchase an efficient donor cells injecting machine.
C．Origen has joined hands with Embrex in producing cell-injecting machines.
D．Origen is the leading company in producing embryo-locating machines.